

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#include "tinyalsa/asoundlib.h"
#include "PCM_Player.h"

#define ID_RIFF 0x46464952
#define ID_WAVE 0x45564157
#define ID_FMT  0x20746d66
#define ID_DATA 0x61746164

struct riff_wave_header {
    uint32_t riff_id;
    uint32_t riff_sz;
    uint32_t wave_id;
};

struct chunk_header {
    uint32_t id;
    uint32_t sz;
};

struct chunk_fmt {
    uint16_t audio_format;
    uint16_t num_channels;
    uint32_t sample_rate;
    uint32_t byte_rate;
    uint16_t block_align;
    uint16_t bits_per_sample;
};


static struct pcm *pcm;


int check_param(struct pcm_params *params, unsigned int param, unsigned int value,
                 char *param_name, char *param_unit)
{
    unsigned int min;
    unsigned int max;
    int is_within_bounds = 1;

    min = pcm_params_get_min(params, (pcm_param)param);
    if (value < min) {
        fprintf(stderr, "%s is %u%s, device only supports >= %u%s\n", param_name, value,
                param_unit, min, param_unit);
        is_within_bounds = 0;
    }

    max = pcm_params_get_max(params, (pcm_param)param);
    if (value > max) {
        fprintf(stderr, "%s is %u%s, device only supports <= %u%s\n", param_name, value,
                param_unit, max, param_unit);
        is_within_bounds = 0;
    }

    return is_within_bounds;
}

int sample_is_playable(unsigned int card, unsigned int device, unsigned int channels,
                        unsigned int rate, unsigned int bits, unsigned int period_size,
                        unsigned int period_count)
{
    struct pcm_params *params;
    int can_play;

    params = pcm_params_get(card, device, PCM_OUT);
    if (params == NULL) {
        fprintf(stderr, "Unable to open PCM device %u.\n", device);
        return 0;
    }

    can_play = check_param(params, PCM_PARAM_RATE, rate, "Sample rate", "Hz");
    can_play &= check_param(params, PCM_PARAM_CHANNELS, channels, "Sample", " channels");
    can_play &= check_param(params, PCM_PARAM_SAMPLE_BITS, bits, "Bitrate", " bits");
    can_play &= check_param(params, PCM_PARAM_PERIOD_SIZE, period_size, "Period size", "Hz");
    can_play &= check_param(params, PCM_PARAM_PERIODS, period_count, "Period count", "Hz");

    pcm_params_free(params);

    return can_play;
}

int play_sample(unsigned int card, unsigned int device, unsigned int channels,
                 unsigned int rate, unsigned int bits, unsigned int period_size,
                 unsigned int period_count)
{
    struct pcm_config config;
    // struct pcm *pcm;
    // char *buffer;

    config.channels = channels;
    config.rate = rate;
    config.period_size = period_size;
    config.period_count = period_count;
    switch (bits) {
    case 32:
        config.format = PCM_FORMAT_S32_LE;
        break;
    case 24:
        config.format = PCM_FORMAT_S24_LE;
        break;    
    case 16:
        config.format = PCM_FORMAT_S16_LE;
        break;
    case 8:
        config.format = PCM_FORMAT_S8;
        break;
    default: 
        config.format = PCM_FORMAT_MAX;
        break;
    }
    config.start_threshold = 0;
    config.stop_threshold = 0;
    config.silence_threshold = 0;

    if (!sample_is_playable(card, device, channels, rate, bits, period_size, period_count)) {
        return -1;
    }

    pcm = pcm_open(card, device, PCM_OUT, &config);
    if (!pcm || !pcm_is_ready(pcm)) {
        fprintf(stderr, "Unable to open PCM device %u (%s)\n",
                device, pcm_get_error(pcm));
        return -2;
    }

    int size = pcm_frames_to_bytes(pcm, pcm_get_buffer_size(pcm));
    

    printf("Playing sample: %u ch, %u hz, %u bit\n", channels, rate, bits);

    return size;
}


int pcm_play_init(int channels, int sample_rate, int format)
{
    unsigned int card = 2;
    unsigned int device = 0;
    unsigned int period_size = 1024;
    unsigned int period_count = 4;

    if (channels > 2) channels = 2;

    if (pcm) {
        pcm_play_exit();
    }

    return play_sample(card, device, channels, sample_rate,
            format, period_size, period_count);

}

void pcm_play_exit()
{
    if (pcm) {
        pcm_close(pcm);
        pcm = NULL;
    }
}

int pcm_playing(char *buffer, unsigned int len)
{
    if (!pcm)
        return -1;
    return pcm_write(pcm, buffer, len);
}

#if 0
int main(int argc, char **argv)
{
    FILE *file;
    struct riff_wave_header riff_wave_header;
    struct chunk_header chunk_header;
    struct chunk_fmt chunk_fmt;
    unsigned int device = 0;
    unsigned int card = 0;
    unsigned int period_size = 1024;
    unsigned int period_count = 4;
    char *filename;
    int more_chunks = 1;

    if (argc < 2) {
        fprintf(stderr, "Usage: %s file.wav [-D card] [-d device] [-p period_size]"
                " [-n n_periods] \n", argv[0]);
        return 1;
    }

    filename = argv[1];
    file = fopen(filename, "rb");
    if (!file) {
        fprintf(stderr, "Unable to open file '%s'\n", filename);
        return 1;
    }

    fread(&riff_wave_header, sizeof(riff_wave_header), 1, file);
    if ((riff_wave_header.riff_id != ID_RIFF) ||
        (riff_wave_header.wave_id != ID_WAVE)) {
        fprintf(stderr, "Error: '%s' is not a riff/wave file\n", filename);
        fclose(file);
        return 1;
    }

    do {
        fread(&chunk_header, sizeof(chunk_header), 1, file);

        switch (chunk_header.id) {
        case ID_FMT:
            fread(&chunk_fmt, sizeof(chunk_fmt), 1, file);
            /* If the format header is larger, skip the rest */
            if (chunk_header.sz > sizeof(chunk_fmt))
                fseek(file, chunk_header.sz - sizeof(chunk_fmt), SEEK_CUR);
            break;
        case ID_DATA:
            /* Stop looking for chunks */
            more_chunks = 0;
            break;
        default:
            /* Unknown chunk, skip bytes */
            fseek(file, chunk_header.sz, SEEK_CUR);
        }
    } while (more_chunks);

    /* parse command line arguments */
    argv += 2;
    while (*argv) {
        if (strcmp(*argv, "-d") == 0) {
            argv++;
            if (*argv)
                device = atoi(*argv);
        }
        if (strcmp(*argv, "-p") == 0) {
            argv++;
            if (*argv)
                period_size = atoi(*argv);
        }
        if (strcmp(*argv, "-n") == 0) {
            argv++;
            if (*argv)
                period_count = atoi(*argv);
        }
        if (strcmp(*argv, "-D") == 0) {
            argv++;
            if (*argv)
                card = atoi(*argv);
        }
        if (*argv)
            argv++;
    }


    int size = pcm_play_init(chunk_fmt.num_channels, chunk_fmt.sample_rate, chunk_fmt.bits_per_sample);
    printf("size=%d\n", size);

    char *buffer;
    buffer = malloc(size);
    if (!buffer) {
        fprintf(stderr, "Unable to allocate %d bytes\n", size);
        free(buffer);
        pcm_close(pcm);
        return -3;
    }

    int num_read;
    do {
        num_read = fread(buffer, 1, size, file);
        if (num_read > 0) {
            if (pcm_play(buffer, num_read)) {
                fprintf(stderr, "Error playing sample\n");
                break;
            }
        }
    } while (num_read > 0);
    
    pcm_play_exit();
    fclose(file);

    return 0;
}
#endif //0












